Service providers offer packet-switched voice applications such as voice over Internet Protocol (VoIP) that allow users to place and receive calls over a wireless communication network such as a network that operates according to the Long Term Evolution (LTE) standards. For example, voice over LTE (VoLTE) is a VoIP application provided by service providers using an Internet Multimedia Subsystem (IMS) core network within an LTE network. The voice quality perceived by users is one of the key performance indicators (KPIs) used to assess the performance of VoLTE applications. Users are able to detect audio interruptions of more than approximately a half second. An absence of audio or an audio interruption that lasts for less than a half of a second has little or no impact on the perceived voice quality. However, an absence of audio or an audio interruption that lasts for more than a half second degrades the perceived voice quality. Application layer monitoring tools are able to detect audio interruptions for packet-switched voice applications such as VoLTE, but the application layer monitoring tools lack the ability to diagnose the fundamental causes of the interruptions. Drive testing, collection of trace information, and the like can be used to identify some sources of call interruption, but these methods are time-consuming and are not able to identify the causes if the interruptions do not occur during the drive test or trace collection interval.